1. Field of the Invention
The present invention relates to an image forming apparatus that receives and processes a print job.
2. Description of the Related Art
Among the print methods that change print content from one printed piece to another for printing invoices and direct mails including personal data, use data, and data that vary according to each customer, there is Variable Data Printing (VDP). One technique that supports VDP is Personalized Print Markup Language (PPML). PPML is one type of printer language based on eXtensible Markup Language (XML) and is an open standard. Printing On Demand Initiative (PODi), which is an association for digital printing service, is responsible for the specifications for the PPML.
PPML allows easy description of instructions including operations such as defining a region, within a page, where an object is to be arranged, rendering an object in PostScript (PS), Portable Document Format (PDF), or Joint Photographic Experts Group (JPEG), and arranging the object in a predetermined position within the page.
In other words, while PS, PDF, and JPEG are used for rendering an object on a sheet, PPML is used for controlling a layout engine that arranges such an object on a sheet.
According to PPML, a name of a reusable object which is to be used again is defined. Once the name is defined, the object is referenced by the defined name from then on. This feature is called Reusable Object. The use of the reusable object eliminates the use of the rendering engine to repeatedly rasterize the same object if it is rasterized once.
Further, PPML allows the use of Global Reusable Object. According to the global reusable object, an object having a name defined according to a certain print job can be referenced from a different print job.
An image to be printed on a page is rendered based on template data that determines an arrangement region of the object and print object information kept in a database.
As described above, according to VDP, a user can change the object to be printed for each page. The user can further designate subsequent stage processing for each page. Setting a plurality of subsequent stage processing operations that can be set in one document is called subset finishing.
However, regarding the subset finishing that allows designation of a plurality of subsequent stage processing operations within a document, all the setting requested from the operator cannot be set unless the storage area is limitless. Thus, the maximum number of operations is set for the number of subset finishing operations that can be set.
For example, there may be many thousands of customers to print invoices or brochures. If, for example, the maximum number of times of subset finishing operations of an image forming apparatus used for printing such invoices or brochures is set to 400, the image forming apparatus may not be able to store all the subset finishing setting wanted by the operator.
Thus, conventionally, one print job sent to the image forming apparatus is divided into a plurality of files according to the maximum number of the subset finishing operations. Since the maximum number of the subset finishing operations of each file is determined, the memory area used when the printing is performed will be within the memory area for the subset finishing setting of the image forming apparatus.
However, even if the maximum number of the subset finishing operations is determined, a reusable object that is repeatedly used in one job still is to be defined for each of the files when it is used again.
For example, an object A defined as a reusable object in a first file may be used again in a second file.
In this case, the object A, which is rasterized when the first file is printed, is to be redefined and RIPped again when a second file is printed.
Since the reusable object cannot be used in a different file, the reusable object is deleted from the first file and generated again (RIPped) in the second file. Accordingly, additional regeneration processing is to be performed.
Thus, according to the conventional technique, due to the regeneration processing of the same object, printing performance has been low.
Under such circumstances, according to the conventional technique, as discussed in Japanese Patent Application Laid-Open No. 2007-226465, when one job is divided into a plurality of files, the job is divided according to use frequency of the reusable object used in each page.
Further, the printing performance is improved by transferring the files to a plurality of image forming apparatuses.